Choux: Put water, milk, butter, sugar, and salt in a high saucepan and bring to a boil.
Once it boils, remove from heat, add all the flour at once, and stir vigorously until fully combined; let it dry on the heat for another 2 minutes.
Pour into a large bowl, beat the eggs, and add them in several batches while stirring vigorously.
The batter is ready when you take a scoop with your spatula, let the batter slide off the spatula, and it breaks off nicely at a point; add some more beaten egg if the dough needs to be thinner.
Preheat the oven to 180°C.
Take a baking sheet lined with baking paper.
Put the batter in a piping bag with a round plain nozzle, the diameter of a thick pea.
Pipe low straight lines of about 10 cm, round thick lines, not flat.
Brush with a soft brush with egg wash.
Bake for about 20 minutes until golden brown, lower to 150°C and bake for 5 minutes with the door open so that the moisture escapes and they don't collapse.
Remove from the oven and let cool.
Pastry cream: Put the sugar, cornstarch, and vanilla seeds in a bowl, add the yolks and whisk well.
Stir in 50 ml of milk and whisk well.
Put the rest of the milk and the scraped vanilla pod in a high saucepan and bring to a boil, remove from heat, add the egg mixture, whisk well, and put back on the heat to bring to a boil.
Let it boil briefly while stirring vigorously, pour into a baking dish and cover with plastic wrap to prevent a skin from forming.
Garnish: Melt the chocolate and cream together in a bain-marie or in the microwave, stir until a shiny beautiful ganache forms.
Pour it into an elongated dish; if it thickens, you can always put it back in the microwave.
Make a hole in the middle at the bottom of each éclair with the round piping nozzle.
Stir the pastry cream to loosen it and put it in a piping bag with the round nozzle.
Insert the piping nozzle into the hole and pipe in the cream.
Finish it off with chocolate: dip it into the chocolate ganache, let it drip for a moment, and you're all set to enjoy!
